Messages in this thread |  | | | Date | Fri, 1 Jun 2012 13:29:55 +0200 | | From | Heiko Carstens <> | | Subject | WARNING: at block/blk-cgroup.c:867 |
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Hi Tejun,
for !CONFIG_CFQ_GROUP_IOSCHED the following warning triggered on s390:
------------[ cut here ]------------ WARNING: at block/blk-cgroup.c:867 Modules linked in: Modules linked in: CPU: 3 Not tainted 3.4.0-09547-gfb21aff #1 Process swapper/0 (pid: 1, task: 000000003ff80000, ksp: 000000003ff7f8b8) Krnl PSW : 0704100180000000 00000000003d76ca (blkcg_policy_register+0xca/0xe0) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 EA:3 Krnl GPRS: 0000000000000000 00000000014b85ec 00000000014b85b0 0000000000000000 000000000096fb60 0000000000000000 00000000009a8e78 0000000000000048 000000000099c070 0000000000b6f000 0000000000000000 000000000099c0b8 00000000014b85b0 0000000000667580 000000003ff7fd98 000000003ff7fd70 Krnl Code: 00000000003d76be: a7280001 lhi %r2,1 00000000003d76c2: a7f4ffdf brc 15,3d7680 #00000000003d76c6: a7f40001 brc 15,3d76c8 >00000000003d76ca: a7c8ffea lhi %r12,-22 00000000003d76ce: a7f4ffce brc 15,3d766a 00000000003d76d2: a7f40001 brc 15,3d76d4 00000000003d76d6: a7c80000 lhi %r12,0 00000000003d76da: a7f4ffc2 brc 15,3d765e Call Trace: ([<0000000000b6f000>] initcall_debug+0x0/0x4) [<0000000000989e8a>] cfq_init+0x62/0xd4 [<00000000001000ba>] do_one_initcall+0x3a/0x170 [<000000000096fb60>] kernel_init+0x214/0x2bc [<0000000000623202>] kernel_thread_starter+0x6/0xc [<00000000006231fc>] kernel_thread_starter+0x0/0xc no locks held by swapper/0/1. Last Breaking-Event-Address: [<00000000003d76c6>] blkcg_policy_register+0xc6/0xe0 ---[ end trace b8ef4903fcbf9dd3 ]--- for !CONFIG_CFQ_GROUP_IOSCHED the blkcg_policy_cfq that cfq_init() tries to register with blkcg_policy_register() is in the bss section and therefore initialized with 0.
So the warning in blkcg_policy_register()
if (WARN_ON(pol->pd_size < sizeof(struct blkg_policy_data))) return -EINVAL; will trigger since pd_size == 0.
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